It can be appreciated that shoulder strengthening and rehabilitation apparatus have been in use for years. These apparatus are used for the development of the rotator cuff musculature of a user by isolating the head of the humerus in the glenoid cavity during internal and external rotation. The main problem with conventional shoulder rehabilitation apparatus is that they do not stabilize the shoulder in the most optimal position for strengthening the rotator cuff muscles. In particular, existing apparatus do not allow for resisted scapular retraction as well as adduction of the arm while fixated at 90 degrees, nor do they provide for resisted shoulder internal and external rotation. Also, the prior art does not allow for scapular depression when the arm is at 90 degrees of shoulder abduction. Further, the prior art does not accommodate resisted internal rotation which is usually twice as strong as that of external rotation.
Some exemplary prior art machines include U.S. Pat. No. 4,817,943 that allows for strengthening of the shoulder muscles, but does not allow for mobility and stabilization of the glenohumeral joint which is essential in order to optimally strengthen the rotator cuff. The apparatus disclosed in U.S. Pat. No. 4,944,508 fails to teach the user to maintain a 90 degree angle of the arm and also has to be stabilized to a solid surface, such as a table. In addition, the prior art fails to provide proper stabilization of the humerus and also the availability to stabilize the shoulder blade, while strengthening the rotator cuff with interchangeable levels of the resistances. The disclosure in U.S. Pat. No. 5,058,574 is mainly concerned with fixating the position of the lower arm, rather than allowing for the proper stabilization of the scapula and the humerus which meet to form the shoulder joint.
Another shortcoming in the various apparatus of the prior art is the absence of myofascial release to the pectoral minor or the levator scapulae in order to allow for optimal movement of the shoulder blade. This is essential to properly scapular retract and adduct the arm at 90 degrees of elbow flexion in order to stabilize the glenerohumeral joint. Another problem with conventional shoulder rehabilitation apparatus is the failure to allow for scapular depression with resistance of varying intensities in order to stabilize the shoulder joint when placed in a vertical position at 90 degrees of shoulder abduction.
While the numerous devices and apparatus of the prior art may be suitable for the particular purpose to which they address, they are not suitable for individuals to be able to optimize their shoulder range of motion, strength building and stability, nor do they allow for myofascial release techniques to decrease spasm.